As an example of a laser apparatus, Patent Document 1 below discloses an ultraviolet light source that comprises: a laser light source, which generates a signal light that falls within a range extending from the infrared region to the visible region; an optical amplifier, which amplifies the signal light generated by the laser light source; a wavelength conversion optical system, which converts the wavelength of the signal light amplified by the optical amplifier to ultraviolet light and outputs such; and an excitation light source, which supplies excitation light to the optical amplifier.
In addition, Patent Document 1 below also discloses a light therapy apparatus, an exposure apparatus, and an object inspection apparatus wherein such an ultraviolet light source is used.